Re: may be a buffer overflow problem

I wrote:
> Seeing that this code is exercised thousands of times a day in the
> regression tests and has had a failure rate of exactly zero (and
> yes, the tests do check the output), there must be some reason
> why it's okay.

After looking a little closer, I think the reason why it works in
practice is that there's always a few bytes of zero padding at the
end of struct sqlca_t.

I don't see any value in changing individual code sites that are
depending on that, because there are surely many more, both in
our own code and end users' code.  What I suggest we ought to do
is formalize the existence of that zero pad.  Perhaps like this:

     char        sqlstate[5];
+    char        sqlstatepad;     /* nul terminator for sqlstate */
 };

Another way could be to change

-     char        sqlstate[5];
+     char        sqlstate[6];

but I fear that could have unforeseen consequences in code that
is paying attention to sizeof(sqlstate).

Either way there are probably doc adjustments to be made.

            regards, tom lane